The present invention relates to an improvement on a solid-gas contact reactor for dirty gas such as exhaust gas of a sintering furnace or a coking oven using coal or heavy oil and, more particularly, to such reactor of upright type in which the troubles due to a piling up of dust are eliminated.
The conventional solid-gas contact reactor is shown in FIGS. 1A to 1D. As will be clear from these figures, it is composed of a plurality of packages of catalyst layers each composed of a plurality of relatively short, identical honeycomb catalysts 1 stacked in a frame structure 2. The plurality of the packages of catalyst layers are mounted on a support base 3 provided for each stage of the reactor. Although the cross sectional shape of each gas passage of the honeycomb catalyst is shown as being reactangular in FIG. 1A, it may be hexagonal or triangular.
With this structure, a gas flow 7 in the down stream side of the support base 3 tends to drift. In addition to this, since the flow rate of the gas is relatively low, there may be vortices in a peripheral area of a lower surface of the support base 3 adjacent to a wall 6 of the reactor and dust 4 may pile up around the peripheral area with time, as shown in FIG. 1D. This tendency is enhanced when the dust is viscous.
When the accumulation of the dust 4 exceeds a certain level, it tends to fall down into the gas passages 5 and the end faces of the catalyst layers in the subsequent stage by gravity or other externally applied vibrations etc., resulting in a substantial pressure loss in the reactor and renders impossible a continuous, long period of operation and further, the performance of the catalyst itself is degraded.
Further, dust accumulates on areas a between the adjacent frame structures 2 and areas b between the frame structure 2 and the reactor wall 6 on the upstream side of the gas flow. The dust ends to fall downwardly due to external forces etc. and clog the gas passages 5 of the catalyst layers thereof, causing the same problems to occur as mentioned previously concerning the down stream side.